Nr pdcp preservation upon rrc resume/suspend

ABSTRACT

According to some embodiments, a method for use in a user equipment (UE) of resuming a radio bearer in a wireless communication network comprises: establishing a radio resource control (RRC) connection with a first network node; receiving a connection suspend message from the first network node; storing a configuration of a radio bearer associated with the RRC connection; suspending the radio bearer associated with the RRC connection; receiving a connection resume message; determining whether the connection resume message includes configuration information for NR packet data convergence protocol (PDCP) for the suspended radio bearer; upon determining the connection resume message includes configuration information for a NR PDCP, configuring the suspended radio bearer with the configuration information; and resuming the suspended radio bearer.

TECHNICAL FIELD

Particular embodiments are directed to wireless communications and, moreparticularly, to preserving new radio (NR) packet data convergenceprotocol (PDCP) connections upon resuming a suspended radio resourcecontrol (RRC) connection.

INTRODUCTION

Third Generation Partnership Project (3GPP) defines a fifth generation(5G) of wireless communication that includes new radio (NR). In atypical wireless, cellular, or radio communications network, wirelessdevices, also known as mobile stations, terminals, and/or User Equipment(UE), communicate via a Radio-Access Network (RAN) with one or more corenetworks. The RAN covers a geographical area that is divided into cells.Each cell is served by a base station (e.g., a radio base station (RBS),or network node, which in some networks may also be referred to as, forexample, a “NodeB”, “eNodeB” or “eNB”). A cell is a geographical areawhere radio coverage is provided by the radio base station at a basestation site or an antenna site in case the antenna and the radio basestation are not collocated. One radio base station may serve one or morecells.

Specifications for the evolved packet system (EPS) have been completedwithin the 3GPP and this work continues in the coming 3GPP releases. TheEPS comprises the evolved universal terrestrial radio-access network(E-UTRAN), also known as long term evolution (LTE), radio access, andthe evolved packet core (EPC), also known as system architectureevolution (SAE) core network. E-UTRAN/LTE is a variant of a 3GPPradio-access technology wherein the radio base station nodes aredirectly connected to the EPC core network rather than to RNCs. Ingeneral, in E-UTRAN/LTE the functions of a RNC are distributed betweenthe radio base station nodes (e.g., eNodeBs in LTE) and the corenetwork. The RAN of an EPS has an essentially flat architecturecomprising radio base station nodes without reporting to RNCs.

Radio resource control (RRC) may be used in the control plane. The mainfunctions of the control plane include the following: broadcast ofsystem information for both non-access stratum (NAS) and access stratum(AS) paging; RRC connection handling; allocation of temporaryidentifiers for the UE; configuration of signaling radio bearer(s) forRRC connection; handling of radio bearers; quality-of-service (QoS)management functions; security functions including key management;mobility functions (including UE measurement reporting and control ofthe reporting, handover, UE cell selection and reselection and controlof cell selection and reselection); and NAS direct message transferto/from the UE.

One packet data convergence protocol (PDCP) entity exists for each radiobearer for the UE. PDCP is used for both control plane (i.e., RRC) andfor user plane (i.e., user data received via GPRS tunnelingprotocol-user tunneling (GTP-U) signaling). A main function of thecontrol plane is ciphering/deciphering and integrity protection. Mainfunctions of the user plane include: ciphering/deciphering, headercompression and decompression using robust header compression (ROHC) andin-sequence delivery, duplicate detection and retransmission.

LTE includes a dual connectivity feature. E-UTRAN supports dualconnectivity (DC) operation whereby a multiple Rx/Tx UE in RRC_CONNECTEDis configured to utilize radio resources provided by two distinctschedulers, located in two eNBs connected via a non-ideal backhaul overthe X2 interface (see 3GPP 36.300). An eNB involved in DC for a certainUE may assume two different roles: an eNB may either act as an MN(Master node) or as an SN (Secondary node). In DC, a UE is connected toone MN and one SN.

In LTE DC, the radio protocol architecture that a particular bearer usesdepends on how the bearer is setup. Three bearer types exist: MCG(Master Cell Group) bearer, SCG (Secondary Cell Group) bearer and splitbearers. RRC is located in MN and SRBs (Signaling Radio Bearers) arealways configured as MCG bearer type and therefore only use the radioresources of the MN. An example is illustrated in FIG. 1.

FIG. 1 is a block diagram illustrating the LTE dual connectivity userplane. The master node includes a MCG bearer and a split bearer. Thesecondary node includes a SCG bearer.

LTE NR also includes dual connectivity. LTE-NR (New Radio) DC may alsobe referred to as LTE-NR tight interwvorking. The major changes from LTEDC are: (a) the introduction of split bearer from the SN (known as SCGsplit bearer); (b) the introduction of split bearer for RRC; and (c) theintroduction of a direct RRC from the SN (also referred to as SCG SRB).Examples are illustrated in FIGS. 2 and 3.

FIG. 2 is a block diagram illustrating LTE-NR tight interworking userplane. The master node includes a MCG bearer and a MCG split bearer. Thesecondary node includes a SCG bearer and a SCG split bearer.

FIG. 3 is a block diagram illustrating LTE-NR tight interworking controlplane. FIG. 3 illustrates protocol layer interaction between the masternode, secondary node, and user equipment.

The SN is sometimes referred to as SgNB (where gNB is an NR basestation), and the MN as MeNB in case the LTE is the master node and NRis the secondary node. In the other case where NR is the master and LTEis the secondary node, the corresponding terms are SeNB and MgNB.

Split RRC messages are mainly used for creating diversity, and thesender can decide to either choose one of the links for scheduling theRRC messages, or it can duplicate the message over both links. In thedownlink, the path switching between the MCG or SCG legs or duplicationon both is left to network implementation. On the other hand, foruplink, the network configures the UE to use the MCG, SCG or both legs.The terms “leg” and “path” are used interchangeably herein.

The following terminologies are used to differentiate different dualconnectivity scenarios: DC: LTE DC (i.e., both MN and SN employ LTE);EN-DC: LTE-NR dual connectivity where LTE is the master and NR is thesecondary; NE-DC: LTE-NR dual connectivity where NR is the master andLTE is the secondary; NR-DC (or NR-NR DC): both MN and SN employ NR; andMR-DC (multi-RAT DC): a generic term to describe where the MN and SNemploy different RATs (EN-DC and NE-DC are two different example casesof MR-DC)

NR harmonizes what were formerly called MCG bearers, MCG split bearers,SCG bearers and SCG split bearers in the following way. It is possibleto configure the UE to use NR PDCP for all the bearers (even when the UEis operating in standalone LTE mode and EN-DC is not setup). For allbearers configured with NR PDCP, it is possible to configure the UE toeither use KeNB or S-KeNB as security key. The configuration of the PDCPlayers is separated from the configuration of the lower layers of theMCG and SCG leg.

From a UE point of view, there are only 3 different bearers (as seen inFIG. 4) namely: (a) the MCG bearer which uses the radio of the MN nodeonly; (b) the SCG bearer which uses the radio of the SN node only; and(c) the split bearer which uses the radio of both the MN and SN.

FIG. 4 is a block diagram illustrating three dual connectivity bearersfrom the perspective of a user equipment. Where the bearers areterminated in the network is not important from the UEs perspectiveanymore (i.e., the UE will just use the key that is being configuredfrom each bearer). NR supports MCG bearer termination in the SN nodeusing S-KeNB and SCG bearer termination in the MN node. Similarly, it ispossible to support both SN and MN terminated bearers at the same time(i.e., both SN terminated split bearers and MN terminated splitbearers.)

LTE includes RRC suspend and resume functionality. A suspended UE can beconsidered to be in an intermediate state between IDLE and CONNECTED,where the UE AS context is kept both at the UE and RAN, and the UE canbe seen as if it is in connected mode from the core network (CN) pointof view and in IDLE mode from the RAN point of view. An advantage ofoperating in this mode is reduced signaling towards the CN and fastertransition to CONNECTED mode as compared to legacy IDLE-CONNECTED modetransitions, while maintaining the UE power saving advantages of IDLEmode. Both LTE rel-15 and NR may support enhanced version of thesuspend/resume functionality (referred to as a lightly connected UE inLTE and inactive mode in NR).

In LTE, when the network decides to move the UE to the inactive state,the eNB sends the UE an RRCConnectionRelease message with the releasecause value of rrc-suspend and it is also provided with a Resume ID. TheUE stores the resumeIdentity and UE AS context (including the currentRRC configuration, the current security context, the PDCP stateincluding ROHC state, C-RNTI used in the source PCell, the cellIdentityand the physical cell identity of the source PCell;); re-establishes allRLC entities (both for SRBs and DRBs); and suspends all DRBs and SRBsexcept SRB0. An example is illustrated in FIG. 5.

FIG. 5 is a sequence diagram illustrating the RRC connection suspendprocedure. At step 1, based on some triggers (e.g., the expiry of a UEinactivity timer) the eNB decides to suspend the RRC connection. At step2, the eNB initiates the S1-AP UE Context Suspend procedure to informthe MME that the RRC connection is being suspended. At step 3, the MMErequests the S-GW to release all S1-U bearers for the UE. At step 4, theMME Acks step 2. At step 5, the eNB suspends the RRC connection bysending an RRCConnectonRelease message with the releaseCause set torrc-Suspend. The message includes the resumeIdentity which is stored bythe UE. At step 6, the UE stores the AS context, suspends all SRBs andDRBs. and UE enters RRC_IDLE light connected state.

When the UE later wants to resume the connection (in response to uplinkdata to be sent or a paging request for downlink data), it sends anRRCConnectionResumeRequest message with the saved resumeIdentity. TheeNB responds with an RRCConnectionResume message, and both the UE andeNB restore the saved UE context, and data transmission/receptionfrom/to the UE can be resumed.

The resume operation can be performed in an eNB other than the eNB thatwas serving the UE when the UE was suspended. In that case, the new eNBcan perform a context fetch e.g., by using the Retrieve UE Contextprocedure from the old eNB (as the resumeIdentity includes informationabout the old eNB/cell). Examples are illustrated in FIGS. 6 and 7.

FIG. 6 is a sequence diagram illustrating the RRC connection resumeprocedure in the same eNB. At step 1, at some later point in time (e.g.,when the UE is being paged or when new data arrives in the uplinkbuffer) the UE resumes the connection by sending anRRCConnectionResumeRequest to the eNB. The UE includes its Resume ID,the establishment cause, and authentication token. The authenticationtoken is calculated in the same way as the short MAC-I used in RRCconnection re-establishment and allows the eNB to verify the UEidentity.

At step 2, provided that the Resume ID exists, and the authenticationtoken is successfully validated, the eNB responds with anRRCConnectionResume. The message includes the next hop chaining count(NCC) value which is required to re-establish the AS security.

At step 3, the UE resumes all SRBs and DRBs and re-establishes the ASsecurity. The UE is now in RRC_CONNECTED. At step 4, the UE respondswith an RRCConnectionResumeComplete confirming that the RRC connectionwas resumed successfully. At step 5, the eNB initiates the S1-AP ContextResume procedure to notify the MME about the UE state change. At step 6,the MME requests the S-GW to activate the S1-U bearers for the UE. Atstep 7, the MME Acks step 5.

FIG. 7 is a sequence diagram illustrating the RRC connection resumeprocedure in a new eNB. Step 1 is the same as step 1 in FIG. 6. At step2, the new eNB locates the old eNB using the Resume ID and retrieves theUE context by means of the X2-AP Retrieve UE Context procedure. At step3, the old eNB responds with the UE context associated with the ResumeID.

Steps 4-6 are the same as step 2-4, respectively, in FIG. 6. At step 7,the new eNB initiates the S1-AP Path Switch procedure to establish a S1UE associated signalling connection to the serving MME and to requestthe MME to resume the UE context.

At step 8, the MME requests the S-GW to activate the S1-U bearers forthe UE and updates the downlink path. At step 9, the MME Acks step 7. Atstep 10, after the S1-AP Path Switch procedure, the new eNB triggersrelease of the UE context at the old eNB by means of the X2-AP UEContext Release procedure.

A particular problem is that existing RRC messages cannot correctlyhandle all the scenarios described above. The contents of theRRCConnectionResume message and the optionalRadioResourceConfigDedicated IE included therein are:

RRCConnectionResume Message

-- ASN1START RRCConnectionResume-r13 ::= SEQUENCE {rrc-TransactionIdentifier , criticalExtensions CHOICE { c1 CHOICE {rrcConnectionResume-r13 RRCConnectionResume-r13-IEs, spare3 NULL, spare2NULL, spare1 NULL }, criticalExtensionsFuture SEQUENCE { } } }RRCConnectionResume-r13-IEs ::= SEQUENCE {radioResourceConfigDedicated-r13 RadioResourceConfigDedicated OPTIONAL,-- Need ON nextHopChainingCount-r13 NextHopChainingCount, measConfig-r13MeasConfig OPTIONAL, -- Need ON antennaInfoDedicatedPCell-r13AntennaInfoDedicated-v10i0 OPTIONAL, -- Need ON drb-ContinueROHC-r13ENUMERATED {true} OPTIONAL, -- Need OP lateNonCriticalExtension OCTETSTRING OPTIONAL, nonCriticalExtension SEQUENCE { } OPTIONAL } --ASN1STOP

RadioResourceConfigDedicated Information Element

-- ASN1START RadioResourceConfigDedicated ::= SEQUENCE {srb-ToAddModList SRB-ToAddModList OPTIONAL, -- Cond HO-Conndrb-ToAddModList DRB-ToAddModList OPTIONAL, -- Cond HO-toEUTRAdrb-ToReleaseList DRB-ToReleaseList OPTIONAL, -- Need ON mac-MainConfigCHOICE { explicitValue MAC-MainConfig, defaultValue NULL } OPTIONAL, --Cond HO-toEUTRA2 sps-Config SPS-Config OPTIONAL, -- Need ONphysicalConfigDedicated OPTIONAL, -- Need ON ..., [[rlf-TimersAndConstants-r9 RLF-TimersAndConstants-r9 OPTIONAL -- Need ON]], [[ measSubframePatternPCell-r10 MeasSubframePatternPCell-r10OPTIONAL -- Need ON ]], [[ neighCellsCRS-Info-r11 NeighCellsCRS-Info-r11OPTIONAL -- Need ON ]], [[ naics-Info-r12 NAICS-AssistanceInfo-r12OPTIONAL --Need ON ]], [[ neighCellsCRS-Info-r13 NeighCellsCRS-Info-r13OPTIONAL, -- Cond CRSIM rlf-TimersAndConstants-r13RLF-TimersAndConstants-r13 OPTIONAL -- Need ON ]], [[ sps-Config-v14xySPS-Config-v14xy OPTIONAL --Need ON ]] } SRB-ToAddMod ::= SEQUENCE {srb-Identity INTEGER (1..2), rlc-Config CHOICE { explicitValueRLC-Config, defaultValue NULL } OPTIONAL, -- Cond SetuplogicalChannelConfig CHOICE { explicitValue LogicalChannelConfig,defaultValue NULL } OPTIONAL, -- Cond Setup ... } DRB-ToAddMod ::=SEQUENCE { eps-BearerIdentity INTEGER (0..15) OPTIONAL, -- CondDRB-Setup drb-Identity DRB-Identity, pdcp-Config PDCP-Config OPTIONAL,-- Cond PDCP rlc-Config RLC-Config OPTIONAL, -- Cond SetupMlogicalChannelIdentity INTEGER (3..10) OPTIONAL, -- Cond DRB-SetupMlogicalChannelConfig LogicalChannelConfig OPTIONAL, -- Cond SetupM ...,[[ drb-TypeChange-r12 ENUMERATED {toMCG; OPTIONAL, -- Need OPrlc-Config-v1250 RLC-Config-v1250 OPTIONAL -- Need ON ]], [[rlc-Config-v1310 RLC-Config-v1310 OPTIONAL, -- Need ON drb-TypeLWA-r13BOOLEAN OPTIONAL, -- Need ON drb-TypeLWIP-r13 ENUMERATED {lwip,lwip-DL-only, lwip-UL- only, eutran} OPTIONAL -- Need ON ]], [[rlc-Config-v14xy RLC-Config-v14xy OPTIONAL, -- Need ONlwip-UL-Aggregation-r14 BOOLEAN OPTIONAL, -- Cond LWIPlwip-DL-Aggregation-r14 BOOLEAN OPTIONAL, -- Cond LWIP lwa-WLAN-AC-r14ENUMERATED (ac-bk, ac-be, ac-vi, ac-vo} OPTIONAL -- Need OP ]] }

As can be seen above, the DRB-ToAddMod IE that may be included in theRadioResourceConfigDedicated IE contains an LTE PDCP configuration forthe bearers.

Assume that when the UE was suspended, some of the bearers had beenusing NR PDCP. This could be because the UE was operating in EN-DC modeor it could even have been in standalone LTE mode. NR may allow theconfiguration of NR PDCP without the UE being in EN-DC as long as it isNR capable. When such a UE is resumed by receiving the RRCResume messagedepicted above, because the only PDCP configuration that is available isthe LTE pdcp-config IE, any bearer that is being resumed will have touse LTE PDCP. Also, because no pdcp-config is included in theSRB-To-AddMod, the SRBs, had they been using NR PDCP before suspension,will not be resumed with NR PDCP.

Thus, a particular problem is that applying the RRC Resume as in legacyLTE results in the implicit conversion of the PDCP type of all suspendedbearers in to LTE PDCP upon resumption.

Accordingly, an additional reconfiguration is required to change thePDCP back to NR PDCP. This results in unnecessary interruption becauseof the PDCP/RLC re-establishments and possibly RLC/MAC reset that may berequired for converting the PDCP version from LTE back to NR Thereconfiguration may interrupt the ongoing traffic which could mean thatit takes longer time to ramp up the TCP window.

Also, one of the advantages of using NR PDCP, even for standalone LTE,is the possibility to set up the termination point of the concernedbearer either at the MN or SN (transparently to the UE), so that futuretransitions to EN-DC can be performed without additional CN signaling.With the conversion of all the bearers back to LTE PDCP, the terminationpoint of these bearers have to be changed to the MN (if it was not tobegin with), thereby causing unnecessary CN signaling.

Additionally, an error case may happen if the UE was at first in an eNBthat supports NR mode, gets suspended, and is resumed in an eNB thatdoes not support NR mode. This is because the pdcp-config to be includedin the DRB-ToAddMod is optional, so if the network does not want tochange the UE's configuration on resume, it may not include the optionalfields. That is, the UE might end up resuming with NR PDCP version,while the serving eNB does not understand NR PDCP. Therefore,communication maybe not be possible between the UE and the eNB after oreven during the resumption.

SUMMARY

The embodiments described herein solve particular problems of thecurrent long term evolution (LTE) Resume/Suspend procedure that resultsin the implicit conversion of all of the user equipment's (UE's) bearersto use LTE packet data convergence protocol (PDCP) upon resumption, evenif they were using new radio (NR) PDCP version.

According to some embodiments, a method for use in a user equipment (UE)of resuming a radio bearer in a wireless communication networkcomprises: establishing a radio resource control (RRC) connection with afirst network node; receiving a connection suspend message from thefirst network node; storing a configuration of a radio bearer associatedwith the RRC connection; suspending the radio bearer associated with theRRC connection; receiving a connection resume message; determiningwhether the connection resume message includes configuration informationfor NR PDCP for the suspended radio bearer; upon determining theconnection resume message includes configuration information for a NRPDCP, configuring the suspended radio bearer with the configurationinformation; and resuming the suspended radio bearer.

In particular embodiments, the established RRC connection includes a NRPDCP bearer or a LTE PDCP bearer. The connection resume message may bereceived from a second network node that is different than the firstnetwork node.

In particular embodiments, configuring the suspended radio bearercomprises using the configuration information in the connection resumemessage and the stored configuration information. The configurationinformation in the connection resume message may take precedence overthe stored configuration information. The configuration information inthe connection resume message may include security information differentfrom the security information used prior to suspension of the radiobearer.

In particular embodiments, the method further comprises, upondetermining the connection resume message does not include configurationinformation for NR PDCP for the suspended radio bearer, resuming thesuspended radio bearer as a LTE PDCP bearer. The method may furthercomprise: establishing a signaling radio bearer 1 (SRB1) NR PDCPconnection with the first network node; and upon receiving theconnection suspend message, converting (920) the SRB1 connection to aLTE PDCP connection. The connection resume message is received over theSRB1 connection.

According to some embodiments, a UE is capable of resuming a radiobearer in a wireless communication network. The UE comprises processingcircuitry operable to: establish a RRC connection with a first networknode; receive a connection suspend message from the first network node;store a configuration of a radio bearer associated with the RRCconnection; suspend the radio bearer associated with the RRC connection;receive a connection resume message; determine whether the connectionresume message includes configuration information for NR PDCP for thesuspended radio bearer; upon determining the connection resume messageincludes configuration information for a NR PDCP, configure thesuspended radio bearer with the configuration information; and resumethe suspended radio bearer.

In particular embodiments, the established RRC connection includes a NRPDCP bearer or a (LTE PDCP bearer. The connection resume message may bereceived from a second network node that is different than the firstnetwork node.

In particular embodiments, the processing circuitry is operableconfigure the suspended radio bearer by using the configurationinformation in the connection resume message and the storedconfiguration information. The configuration information in theconnection resume message may take precedence over the storedconfiguration information. The configuration information in theconnection resume message may include security information differentfrom the security information used prior to suspension of the radiobearer.

In particular embodiments, the processing circuitry is further operableto, upon determining the connection resume message does not includeconfiguration information for a NR PDCP for the suspended radio bearer,resume the suspended radio bearer as a LTE PDCP bearer. The processingcircuitry may be further operable to: establish a SRB1 NR PDCPconnection with the first network node; upon receiving the connectionsuspend message and convert the SRB1 connection to a LTE PDCPconnection. The processing circuitry is operable to receive theconnection resume message over the SRB1 connection.

According to some embodiments, a method for use in a network node ofresuming a radio bearer in a wireless communication network comprises:determining to resume, with a UE, a radio bearer associated with a RRCconnection; and sending a connection resume message to the userequipment. The connection resume message includes configurationinformation for NR PDCP for the radio bearer.

In particular embodiments, configuration information for the radiobearer to resume previously included NR PDCP configuration informationor LTE configuration information.

In particular embodiments, the method further comprises: receivingcapability information for the UE; and determining the UE is capable ofsupporting NR PDCP based on the capability information. The method mayfurther comprise: establishing a SRB1 NR PDCP connection with the UE;sending a connection suspend message to the UE; and receiving aconnection reconfiguration message from the UE reconfiguring the SRB1from NR PDCP to LTE PDCP.

According to some embodiments, a network node is capable of resuming aradio bearer in a wireless communication network. The network nodecomprises processing circuitry operable to: determine to resume, withUE, a radio bearer associated with a RRC connection; and send aconnection resume message to the user equipment. The connection resumemessage includes configuration information for NR PDCP for the radiobearer.

In particular embodiments, configuration information for the radiobearer to resume previously included NR PDCP configuration informationor LTE configuration information.

In particular embodiments, the processing circuitry is further operableto: receive capability information for the UE; and determine the UE iscapable of supporting NR PDCP based on the capability information. Theprocessing circuitry may be further operable to: establish a SRB1 NRPDCP connection with the UE; send a connection suspend message to theUE; and receive a connection reconfiguration message from the UEreconfiguring the SRB1 from NR PDCP to LTE PDCP.

According to some embodiments, a UE is capable of resuming a radiobearer in a wireless communication network. The UE comprises aconfiguration module and a receiving module. The configuration module isoperable to establish a RRC connection with a first network node. Thereceiving module is operable to receive a connection suspend messagefrom the first network node. The configuration module is furtheroperable to: store a configuration of a radio bearer associated with theRRC connection and suspend the radio bearer associated with the RRCconnection. The receiving module is further operable to receive aconnection resume message. The configuration module is further operableto: determine whether the connection resume message includesconfiguration information for NR PDCP for the suspended radio bearer.Upon determining the connection resume message includes configurationinformation for a NR PDCP, configure the suspended radio bearer with theconfiguration information and resume the suspended radio bearer.

According to some embodiments, a network node is capable of resuming aradio bearer in a wireless communication network. The network nodecomprises a configuration module and a transmitting module. Theconfiguration module is operable to determine to resume, with a UE, aradio bearer associated with a RRC connection. The transmitting moduleis operable to send a connection resume message to the user equipment.The connection resume message includes configuration information for NRPDCP for the radio bearer.

Also disclosed is a computer program product. The computer programproduct comprises instructions stored on non-transient computer-readablemedia which, when executed by a processor, perform the steps of:establishing a radio resource control (RRC) connection with a firstnetwork node; receiving a connection suspend message from the firstnetwork node: storing a configuration of a radio bearer associated withthe RRC connection; suspending the radio bearer associated with the RRCconnection; receiving a connection resume message; determining whetherthe connection resume message includes configuration information for NRPDCP for the suspended radio bearer; upon determining the connectionresume message includes configuration information for a NR PDCP,configuring the suspended radio bearer with the configurationinformation; and resuming the suspended radio bearer.

Another computer program product comprises instructions stored onnon-transient computer-readable media which, when executed by aprocessor, perform the steps of: determining to resume, with a UE, aradio bearer associated with a RRC connection; and sending a connectionresume message to the user equipment. The connection resume messageincludes configuration information for NR PDCP for the radio bearer.

Certain embodiments of the present disclosure may provide one or moretechnical advantages. For example, some embodiments may suspend andresume all the relevant bearers of a UE, while preserving the PDCPversion that was being used before suspension, thereby eliminating theneed to do further re-configurations or core network signaling to bringthe UE's bearers and the corresponding network configuration for that UEto the same configuration they were before the UE's suspension.Eliminating reconfigurations has a significant performance advantage inthat the uplink and downlink user data can continue to flow enablingprotocols like Transmission Control Protocol (TCP) to speed up the rampof the TCP windows which increases link utilization. Other advantagesmay be readily available to one having skill in the art. Certainembodiments may have none, some, or all of the recited advantages.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the embodiments and their featuresand advantages, reference is now made to the following description,taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a block diagram illustrating the LTE dual connectivity userplane;

FIG. 2 is a block diagram illustrating LTE-NR tight interworking userplane:

FIG. 3 is a block diagram illustrating LTE-NR tight interworking controlplane;

FIG. 4 is a block diagram illustrating three dual connectivity bearersfrom the perspective of a user equipment;

FIG. 5 is a sequence diagram illustrating the RRC connection suspendprocedure:

FIG. 6 is a sequence diagram illustrating the RRC connection resumeprocedure in the same eNB:

FIG. 7 is a sequence diagram illustrating the RRC connection resumeprocedure in a new eNB;

FIG. 8 is a block diagram illustrating an example wireless network,according to a particular embodiment:

FIG. 9 is a flow diagram illustrating an example method in a wirelessdevice, according to particular embodiments;

FIG. 10 is a flow diagram illustrating an example method in a networknode, according to particular embodiments;

FIG. 11A is a block diagram illustrating an example embodiment of awireless device;

FIG. 11B is a block diagram illustrating example components of awireless device:

FIG. 12A is a block diagram illustrating an example embodiment of anetwork node; and

FIG. 12B is a block diagram illustrating example components of a networknode.

DETAILED DESCRIPTION

Third Generation Partnership Project (3GPP) defines a fifth generation(5G) of wireless communication that includes new radio (NR). NR, similarto long term evolution (LTE), includes dual connectivity. LTE and NRalso include radio resource control (RRC) suspend and resumefunctionality. A particular problem is that LTE RRC messages cannotcorrectly handle all the scenarios for NR RRC suspend and resume withrespect to packet data convergence protocol (PDCP) connections in NR.

Particular embodiments described herein obviate the problems describedabove and include procedures that prevent the implicit conversion of allof the user equipment's (UE's) bearers to use LTE PDCP upon resumptionif the UEs were using NR PDCP before suspension. Some embodiments maysuspend and resume all the relevant bearers of a UE, while preservingthe PDCP version that was being used before suspension, therebyeliminating the need to do further re-configurations or core networksignaling to bring the UE's bearers and the corresponding networkconfiguration for that UE to the same configuration they were before theUE's suspension. Eliminating reconfigurations has a significantperformance advantage in that the uplink and downlink user data cancontinue to flow enabling protocols like TCP to speed up the ramp of theTCP windows which increases link utilization.

The following description sets forth numerous specific details. It isunderstood, however, that embodiments may be practiced without thesespecific details. In other instances, well-known circuits, structuresand techniques have not been shown in detail in order not to obscure theunderstanding of this description. Those of ordinary skill in the art,with the included descriptions, will be able to implement appropriatefunctionality without undue experimentation.

References in the specification to “one embodiment,” “an embodiment,”“an example embodiment,” etc., indicate that the embodiment describedmay include a particular feature, structure, or characteristic, butevery embodiment may not necessarily include the particular feature,structure, or characteristic. Moreover, such phrases are not necessarilyreferring to the same embodiment. Further, when a particular feature,structure, or characteristic is described in connection with anembodiment, it is submitted that it is within the knowledge of oneskilled in the art to implement such feature, structure, orcharacteristic in connection with other embodiments, whether or notexplicitly described.

Particular embodiments are described with reference to FIGS. 8-12B ofthe drawings, like numerals being used for like and corresponding partsof the various drawings. LTE and NR are used throughout this disclosureas an example cellular system, but the ideas presented herein may applyto other wireless communication systems as well.

FIG. 8 is a block diagram illustrating an example wireless network,according to a particular embodiment. Wireless network 100 includes oneor more wireless devices 110 (such as mobile phones, smart phones,laptop computers, tablet computers, MTC devices, or any other devicesthat can provide wireless communication) and a plurality of networknodes 120 (such as base stations or eNodeBs). Wireless device 110 mayalso be referred to as a UE. Network node 120 serves coverage area 115(also referred to as cell 115).

In general, wireless devices 110 that are within coverage of networknode 120 (e.g., within cell 115 served by network node 120) communicatewith network node 120 by transmitting and receiving wireless signals130. For example, wireless devices 110 and network node 120 maycommunicate wireless signals 130 containing voice traffic, data traffic,and/or control signals. A network node 120 communicating voice traffic,data traffic, and/or control signals to wireless device 110 may bereferred to as a serving network node 120 for the wireless device 110.Communication between wireless device 110 and network node 120 may bereferred to as cellular communication. Wireless signals 130 may includeboth downlink transmissions (from network node 120 to wireless devices110) and uplink transmissions (from wireless devices 110 to network node120).

Each network node 120 may have a single transmitter or multipletransmitters for transmitting signals 130 to wireless devices 110. Insome embodiments, network node 120 may comprise a multi-inputmulti-output (MIMO) system. Wireless signal 130 may comprise one or morebeams. Particular beams may be beamformed in a particular direction.Each wireless device 110 may have a single receiver or multiplereceivers for receiving signals 130 from network nodes 120 or otherwireless devices 110. Wireless device 110 may receive one or more beamscomprising wireless signal 130.

Wireless signals 130 may be transmitted on time-frequency resources. Thetime-frequency resources may be partitioned into radio frames,subframes, slots, and/or mini-slots. Network node 120 may dynamicallyschedule subframes/slots/mini-slots as uplink, downlink, or acombination uplink and downlink. Different wireless signals 130 maycomprise different transmission processing times.

Network node 120 may operate in a licensed frequency spectrum, such asan LTE spectrum. Network node 120 may also operate in an unlicensedfrequency spectrum, such as a 5 GHz Wi-Fi spectrum. In an unlicensedfrequency spectrum, network node 120 may coexist with other devices suchas IEEE 802.11 access points and terminals. To share the unlicensedspectrum, network node 120 may perform LBT protocols before transmittingor receiving wireless signals 130. Wireless device 110 may also operatein one or both of licensed or unlicensed spectrum and in someembodiments may also perform LBT protocols before transmitting wirelesssignals 130. Both network node 120 and wireless device 110 may alsooperate in licensed shared spectrum.

For example, network node 120 a may operate in a licensed spectrum andnetwork node 120 b may operate in an unlicensed spectrum. Wirelessdevice 110 may operate in both licensed and unlicensed spectrum. Inparticular embodiments, network nodes 120 a and 120 b may beconfigurable to operate in a licensed spectrum, an unlicensed spectrum,a licensed shared spectrum, or any combination. Although the coveragearea of cell 115 b is illustrated as included in the coverage area ofcell 115 a, in particular embodiments the coverage areas of cells 115 aand 115 b may overlap partially or may not overlap at all.

In particular embodiments, wireless device 110 and network nodes 120 mayperform carrier aggregation. For example, network node 120 a may servewireless device 110 as a PCell and network node 120 b may serve wirelessdevice 110 as a SCell. Network nodes 120 may perform self-scheduling orcross-scheduling. If network node 120 a is operating in licensedspectrum and network node 120 b is operating in unlicensed spectrum,network node 120 a may provide license assisted access to the unlicensedspectrum (i.e., network node 120 a is a LAA PCell and network node 120 bis a LAA SCell).

In particular embodiments, wireless device 110 may have RRC and PDCPconnections with network nodes 120. Wireless device 110 and networknodes 120 may perform dual connectivity. For example, wireless device110 may connect to both network node 120 a and network node 120 b asdescribed with respect to any of FIGS. 1-7. Wireless device 110 andnetwork nodes 120 may suspend and resume PDCP connections. The PDCPconnections may be LTE PDCP connections or NR PDCP connections.Particular examples are described in more detail below with respect toFIGS. 9-12B, for example.

In wireless network 100, each network node 120 may use any suitableradio access technology, such as long term evolution (LTE),LTE-Advanced, UMTS, HSPA, GSM, cdma2000, NR, WiMax, WiFi. and/or othersuitable radio access technology. Wireless network 100 may include anysuitable combination of one or more radio access technologies. Forpurposes of example, various embodiments may be described within thecontext of certain radio access technologies. However, the scope of thedisclosure is not limited to the examples and other embodiments coulduse different radio access technologies.

As described above, embodiments of a wireless network may include one ormore wireless devices and one or more different types of radio networknodes capable of communicating with the wireless devices. The networkmay also include any additional elements suitable to supportcommunication between wireless devices or between a wireless device andanother communication device (such as a landline telephone). A wirelessdevice may include any suitable combination of hardware and/or software.For example, in particular embodiments, a wireless device, such aswireless device 110, may include the components described with respectto FIG. 11A below. Similarly, a network node may include any suitablecombination of hardware and/or software. For example, in particularembodiments, a network node, such as network node 120, may include thecomponents described with respect to FIG. 12A below.

In particular embodiments, to accomplish the resumption of bearers totheir pre-suspension state upon resumption, an information element isincluded in the LTE RRC Resume message that contains the NR PDCPconfigurations for the bearers that are to resume with NR PDCP version.

In some embodiments, the UE will keep the NR PDCP configuration usedwhen the UE was in an RRC connected even after it has left the RRCconnected state. When the UE resumes the RRC connected (enter RRCconnected state) the network will indicate to the UE that it shouldresume the NR PDCP configuration. The network may also indicate if anyparameters of the NR PDCP configuration should be modified.

Furthermore, in some embodiments, the NR PDCP configuration may beresumed using a different security key and/or security algorithm thanthat was used before suspension. The security key to be used may bederived in the UE based on previous keys and other parameters providedby the network e.g. Next Hop Chaining Counter (NCC).

In another embodiment of the invention, if a UE using NR PDCP for someor all of its bearers gets suspended and later on is resumed in an eNBthat doesn't support NR, the RRC Resume message will not contain the NRPDCP configurations and as such all bearers will resume in LTE PDCPversion.

In some embodiments, if a UE using LTE PDCP for all of its bearers getssuspended and later on is resumed in a different eNB, the UE checks tosee if that eNB supports NR (e.g., by looking into the broadcastinformation of the eNB), and if the eNB supports NR, the UE includes anindication in the resume message signifying that it wants to beconfigured with NR PDCP. The target eNB then responds to this byincluding in the RRC Resume message it sends to the UE NR PDCPconfigurations and as such some or all of the bearers can be resumedwith NR PDCP.

In particular embodiments, when a UE was being served by an eNB thatsupports NR PDCP and using NR PDCP for all of or some of its bearersgets suspended, the eNB makes sure that the protocolparameters/configuration such as security parameters (e.g. cipheringalgorithms) and sequence number lengths can also be reused in the LTEPDCP, to make sure the UE can be resumed in an eNB that may not supportNR PDCP. If the configurations currently used by the NR PDCP of the UEwere not compatible with LTE PDCP, a reconfiguration is sent to the UEto change them to compatible values before the UE gets suspended. Thisreconfiguration can be a separate RRC reconfiguration message, or theRRC suspend command is enhanced to included RRC reconfigurations.

In one embodiment of the invention, when a UE resumes in a different eNBand the target eNB doesn't support NR PDCP, the target eNB makes surethat the LTE PDCP config is included in the configurations of all thebearers (even though it is optional parameter) to ensure that all thebearers will be resumed with LTE PDCP version.

In one embodiment of the invention, the UE's NR capability is part ofthe UE's context that is saved by the network/UE when the UE issuspended.

In another embodiment of the invention, when a UE is resuming, and thecontext is being fetched by the target eNB from the source eNB, thesource eNB can include the UE's NR capability to the target eNB, eitherexplicitly (e.g. in an X2 message used for context fetching between thetwo eNBs), or implicitly in the UE context.

In one embodiment, if a UE using LTE PDCP for all of its bearers getssuspended and later on is resumed in a different eNB, and if the targeteNB supports NR and it detects that the UE supports NR, the target eNBcan include in the RRC Resume message it sends to the UE NR PDCPconfigurations, even if the UE's bearers were using LTE PDCP beforesuspension, and as such some or all of the bearers can be resumed withNR PDCP. The NR PDCP parameters that are configured or resumed when theUE returns to an RRC connected state may include sequence number size,status report configuration, discard, or reordering timers.

Additionally the UE may, upon return to RRC connected, be configured totransmit NR PDCP data over LTE or NR radio or both LTE and NR radio. TheUE may also be configured to use NR PDCP for signaling radio bearers(e.g., SRB1, SRB2). The signaling radio bearers may be configured in theUE so that the UE can send or receive signaling over LTE or NR radio orboth LTE and NR radio

FIG. 9 is a flow diagram illustrating an example method in a wirelessdevice, according to particular embodiments. In particular embodiments,one or more steps of FIG. 9 may be performed by wireless device 110 ofnetwork 100 described with respect to FIG. 8.

The method begins at step 912, where a wireless device establishes a RRCconnection with a first network node. For example, wireless device 110may establish a RRC connection with network node 120 a.

At step 914, the wireless device may establish an SRB1 NR PDCPconnection with the first network node. For example, wireless device 110may establish an SRB1 NR PDCP connection with network node 120 fortransfer of RRC signaling messages.

At step 916, the wireless device receives a connection suspend messagefrom the first network node. For example, wireless device 110 mayreceive a RRC Suspend message from network node 120 a.

At step 917, the wireless device stores a configuration of a radiobearer associated with the RRC connection. The wireless device may storeconfiguration information for a NR PDCP bearer or a LTE bearer. Forexample, wireless device 110 may store information about an NR bearerconnection, such as sequence number information, status information,security information, etc. Wireless device 110 may store the informationlocally or at the network node, for example, as part of the UE Context.Wireless device 110 may store the information according to any of theembodiments or examples described above.

At step 918, the wireless device suspends the radio bearer associatedwith the RRC connection. For example, wireless device 110 may suspendthe NR or LTE PDCP radio bearer.

At step 920, the wireless device may convert the SRB1 NR PDCP connectionto a LTE PDCP connection. For example, wireless device 110 may convertthe SRB1 connection established at step 914 into an LTE PDCP connection.A particular advantage is that if any of the suspended bearers areresumed in a different network node that may not support NR, then thewireless device may use the LTE PDCP configuration for the SRB1 to sendan RRC resume request to the network node.

At step 922, the wireless device receives a connection resume messagefrom a second network node. In some embodiments, the second network nodemay be the same as the first network node. In other embodiments, thesecond network node may be different than the first network node. As oneexample, wireless device 110 may receive a RRC Resume message fromnetwork node 120 a. As another example, wireless device 110 may havemoved into range of network node 120 b and may receive a RRC Resumemessage from network node 120 b.

At step 924, the wireless device determines whether the connectionresume message includes configuration information for NR PDCP for thesuspended radio bearer. For example, wireless device 110 may determinethe RRC Resume message includes information for configuring a NR PDCPbearer. The method continues to step 925.

At step 925, the wireless device configures the suspended radio bearerwith the configuration information. For example, wireless device 110configures the suspended radio bearer with the configurationinformation. In some embodiments, wireless device 110 may use acombination of the received configuration and the stored configurationto configure the connection.

At step 926, the wireless device resumes the suspended radio bearer. Forexample, wireless device 110 may resume a NR or LTE radio bearer basedon the configuration from the previous step. The wireless device mayresume the radio bearer according to any of the embodiments or examplesdescribed above.

Modifications, additions, or omissions may be made to method 900 of FIG.9. Additionally, one or more steps in the method of FIG. 9 may beperformed in parallel or in any suitable order. As one example, step 916may be performed after steps 917 or 918 in some embodiments. As anotherexample, step 917 may be performed earlier or later. The steps may berepeated over time as necessary.

FIG. 10 is a flow diagram illustrating an example method in a networknode, according to particular embodiments. In particular embodiments,one or more steps of FIG. 10 may be performed by network node 120 ofnetwork 100 described with respect to FIG. 8.

The method may begin at step 1012, where a network node establishes aSRB1 NR PDCP connection with a UE. For example, network node 120 mayestablish a SRB1 NR PDCP connection with wireless device 110 fortransfer of RRC signaling messages.

At step 1014, the network node may send a connection suspend message tothe UE. For example, network node 120 may send a connection suspendmessage to wireless device 110 to suspend one or more radio bearers.

At step 1016, the network node may receive a connection reconfigurationmessage from the UE reconfiguring the SRB1 from NR PDCP to LTE PDCP. Forexample, network node 120 may receive a connection reconfigurationmessage from wireless device 110. Wireless device may send thereconfiguration message, for example, in case the wireless deviceresumes PDCP bearer connections with a different network node that doesnot support NR PDCP.

At step 1018, the network node determines to resume, with a UE, a radiobearer associated with a RRC connection. For example, network node 120 bmay receive a RRC resume request from wireless device 110 to resume aradio bearer. In some embodiments, the bearer connection may include anysuitable bearer connection.

At step 1020, the network node may receive capability information forthe UE. For example, network node 120 may receive capability informationfrom wireless device 110 indicating capabilities of wireless device 110,such as a capability for communicating using NR PDCP or LTE PDCP.

At step 1022, the network node determines the UE is capable ofsupporting NR PDCP based on the capability information. For example,network node 120 may determine wireless device 110 is capable ofsupporting NR PDCP based on the received capability information.

In some embodiments, the network node may receive NR configurationinformation for the bearer connection from another network node. Forexample, network node 120 b may receive configuration information fromnetwork node 120 a if wireless device 110 was previously connected tonetwork node 120 a before the bearer was suspended. The network node mayreceive NR configuration information according to any of the embodimentsor examples described above.

At step 1024, the network node sends a connection resume message to theUE. The connection resume message includes configuration information forNR PDCP for the radio bearer. For example, network node 120 b may send aRRC Resume message to wireless device 110. The configuration informationmay include NR or LTE configuration information. The configurationinformation may include information according to any of the embodimentsor examples described above.

Modifications, additions, or omissions may be made to method 1000 ofFIG. 10. Additionally, one or more steps in the method of FIG. 10 may beperformed in parallel or in any suitable order. The steps may berepeated over time as necessary.

FIG. 11A is a block diagram illustrating an example embodiment of awireless device. The wireless device is an example of the wirelessdevices 110 illustrated in FIG. 8. In particular embodiments, thewireless device is capable of pausing and resuming NR bearerconnections.

Particular examples of a wireless device include a mobile phone, a smartphone, a PDA (Personal Digital Assistant), a portable computer (e.g.,laptop, tablet), a sensor, a modem, a machine type (MTC) device/machineto machine (M2M) device, laptop embedded equipment (LEE), laptop mountedequipment (LME), USB dongles, a device-to-device capable device, avehicle-to-vehicle device, or any other device that can provide wirelesscommunication. The wireless device includes transceiver 1310, processingcircuitry 1320, memory 1330, and power source 1340. In some embodiments,transceiver 1310 facilitates transmitting wireless signals to andreceiving wireless signals from wireless network node 120 (e.g., via anantenna), processing circuitry 1320 executes instructions to providesome or all of the functionality described herein as provided by thewireless device, and memory 1330 stores the instructions executed byprocessing circuitry 1320. Power source 1340 supplies electrical powerto one or more of the components of wireless device 110, such astransceiver 1310, processing circuitry 1320, and/or memory 1330.

Processing circuitry 1320 includes any suitable combination of hardwareand software implemented in one or more integrated circuits or modulesto execute instructions and manipulate data to perform some or all ofthe described functions of the wireless device. In some embodiments,processing circuitry 1320 may include, for example, one or morecomputers, one more programmable logic devices, one or more centralprocessing units (CPUs), one or more microprocessors, one or moreapplications, and/or other logic, and/or any suitable combination of thepreceding. Processing circuitry 1320 may include analog and/or digitalcircuitry configured to perform some or all of the described functionsof wireless device 110. For example, processing circuitry 1320 mayinclude resistors, capacitors, inductors, transistors, diodes, and/orany other suitable circuit components.

Memory 1330 is generally operable to store computer executable code anddata. Examples of memory 1330 include computer memory (e.g., RandomAccess Memory (RAM) or Read Only Memory (ROM)), mass storage media(e.g., a hard disk), removable storage media (e.g., a Compact Disk (CD)or a Digital Video Disk (DVD)), and/or or any other volatile ornon-volatile, non-transitory computer-readable and/orcomputer-executable memory devices that store information.

Power source 1340 is generally operable to supply electrical power tothe components of wireless device 110. Power source 1340 may include anysuitable type of battery, such as lithium-ion, lithium-air, lithiumpolymer, nickel cadmium, nickel metal hydride, or any other suitabletype of battery for supplying power to a wireless device.

Other embodiments of the wireless device may include additionalcomponents (beyond those shown in FIG. 11A) responsible for providingcertain aspects of the wireless device's functionality, including any ofthe functionality described above and/or any additional functionality(including any functionality necessary to support the solution describedabove).

FIG. 11B is a block diagram illustrating example components of awireless device 110. The components may include configuration module1350, transmitting module 1352 and receiving module 1354.

Configuration module 1350 may perform the configuration functions ofwireless device 110. For example, configuration module 1350 mayestablish a RRC connection, suspend a radio bearer associated with a RRCconnection, determine whether the connection resume message includesconfiguration information for NR PDCP for the suspended radio bearer,configure a suspended radio bearer with configuration information, andresume suspended radio bearers according to any of the examples andembodiments described above. In certain embodiments, configurationmodule 1350 may include or be included in processing circuitry 1320. Inparticular embodiments, configuration module 1350 may communicate withtransmitting module 1352 and receiving module 1354.

Transmitting module 1352 may perform the transmitting functions ofwireless device 110. For example, transmitting module 1352 may establishradio bearers with network node 120 and/or send configurationinformation to network node 120 according to any of the examples andembodiments described above. In certain embodiments, transmitting module1352 may include or be included in processing circuitry 1320. Inparticular embodiments, transmitting module 1352 may communicate withscheduling module 1350 and receiving module 1354.

Receiving module 1354 may perform the receiving functions of wirelessdevice 110. For example, receiving module 1354 may receive suspend andresume messages from network node 120 according to any of the examplesand embodiments described above. In certain embodiments, receivingmodule 1354 may include or be included in processing circuitry 1320. Inparticular embodiments, transmitting module 1352 may communicate withscheduling module 1350 and transmitting module 1352.

FIG. 12A is a block diagram illustrating an example embodiment of anetwork node. The network node is an example of the network node 120illustrated in FIG. 8. In particular embodiments, the network node iscapable of pausing and resuming NR bearer connections.

Network node 120 can be an eNodeB, a nodeB, a base station, a wirelessaccess point (e.g., a Wi-Fi access point), a low power node, a basetransceiver station (BTS), a transmission point or node, a remote RFunit (RRU), a remote radio head (RRH), or other radio access node. Thenetwork node includes at least one transceiver 1410, at least oneprocessing circuitry 1420, at least one memory 1430, and at least onenetwork interface 1440. Transceiver 1410 facilitates transmittingwireless signals to and receiving wireless signals from a wirelessdevice, such as wireless devices 110 (e.g., via an antenna); processingcircuitry 1420 executes instructions to provide some or all of thefunctionality described above as being provided by a network node 120;memory 1430 stores the instructions executed by processing circuitry1420; and network interface 1440 communicates signals to backend networkcomponents, such as a gateway, switch, router, Internet, Public SwitchedTelephone Network (PSTN), controller, and/or other network nodes 120.Processing circuitry 1420 and memory 1430 can be of the same types asdescribed with respect to processing circuitry 1320 and memory 1330 ofFIG. 11A above.

In some embodiments, network interface 1440 is communicatively coupledto processing circuitry 1420 and refers to any suitable device operableto receive input for network node 120, send output from network node120, perform suitable processing of the input or output or both,communicate to other devices, or any combination of the preceding.Network interface 1440 includes appropriate hardware (e.g., port, modem,network interface card, etc.) and software, including protocolconversion and data processing capabilities, to communicate through anetwork.

FIG. 11B is a block diagram illustrating example components of a networknode 120. The components may include configuration module 1450,transmitting module 1452 and receiving module 1454.

Configuration module 1450 may perform the configuration functions ofnetwork node 120. For example, configuration module 1450 may determineto resume a radio bearer and/or configure a radio bearer according toany of the examples and embodiments described above. In certainembodiments, configuration module 1450 may include or be included inprocessing circuitry 1420. In particular embodiments, configurationmodule 1450 may communicate with transmitting module 1452 and receivingmodule 1454.

Transmitting module 1452 may perform the transmitting functions ofnetwork node 120. For example, transmitting module 1452 may send radiobearer configuration information to another network node, and/or resumemessages to a wireless device according to any of the examples andembodiments described above. In certain embodiments, transmitting module1452 may include or be included in processing circuitry 1420. Inparticular embodiments, transmitting module 1452 may communicate withconfiguration module 1450 and receiving module 1454.

Receiving module 1454 may perform the receiving functions of networknode 120. For example, receiving module 1454 may receive radio bearerconfiguration information from another network node or a wireless deviceaccording to any of the examples and embodiments described above. Incertain embodiments, receiving module 1454 may include or be included inprocessing circuitry 1420. In particular embodiments, transmittingmodule 1452 may communicate with configuration module 1450 andtransmitting module 1452.

Modifications, additions, or omissions may be made to the systems andapparatuses disclosed herein without departing from the scope of theinvention. The components of the systems and apparatuses may beintegrated or separated. Moreover, the operations of the systems andapparatuses may be performed by more, fewer, or other components.Additionally, operations of the systems and apparatuses may be performedusing any suitable logic comprising software, hardware, and/or otherlogic. As used in this document. “each” refers to each member of a setor each member of a subset of a set.

Modifications, additions, or omissions may be made to the methodsdisclosed herein without departing from the scope of the invention. Themethods may include more, fewer, or other steps. Additionally, steps maybe performed in any suitable order.

Although this disclosure has been described in terms of certainembodiments, alterations and permutations of the embodiments will beapparent to those skilled in the art. Accordingly, the above descriptionof the embodiments does not constrain this disclosure. Other changes,substitutions, and alterations are possible without departing from thespirit and scope of this disclosure, as defined by the claims below.

Abbreviations used in the preceding description include:

3GPP Third Generation Partnership Project

5G Fifth Generation

BBU Baseband Unit

BTS Base Transceiver Station

CC Component Carrier

D2D Device to Device

DC Dual Connectivity

eMBB Enhanced Mobile Broadband

eNB eNodeB

EPC Evolved Packet Core

EPS Evolved Packet System

FDD Frequency Division Duplex

FFT Fast Fourier Transform

gNB Next-generation NodeB

LAA Licensed-Assisted Access

LBT Listen-before-talk

LTE Long Term Evolution

LTE-U LTE in Unlicensed Spectrum

MeNB Master eNB

M2M Machine to Machine

MCG Master Cell Group

MIB Master Information Block

MIMO Multi-Input Multi-Output

MTC Machine Type Communication

NAS Non-Access Stratum

NR New Radio

OFDM Orthogonal Frequency Division Multiplexing

PCM Parity Check Matrix

PDCP Packet Data Convergence Protocol

PRB Physical Resource Block

QoS Quality of Service

RAN Radio Access Network

RAT Radio Access Technology

RBS Radio Base Station

RNC Radio Network Controller

RRC Radio Resource Control

RRH Remote Radio Head

RRU Remote Radio Unit

SAE System Architecture Evolution

SCell Secondary Cell

SCG Secondary Cell Group

SeNB Secondary eNB

SI System Information

SIB System Information Block

SRB Signaling Radio Bearer

TDD Time Division Duplex

TNL Transport Network Layer

UE User Equipment

UL Uplink

UTRAN Universal Terrestrial Radio Access Network

WAN Wireless Access Network

1. A method for use in a user equipment (UE) of resuming a radio bearerin a wireless communication network, the method comprising: establishinga radio resource control (RRC) connection with a first network node;receiving a connection suspend message from the first network node;storing a configuration of a radio bearer associated with the RRCconnection; suspending the radio bearer associated with the RRCconnection; receiving a connection resume message; determining whetherthe connection resume message includes configuration information for NRpacket data convergence protocol (PDCP) for the suspended radio bearer;upon determining the connection resume message includes configurationinformation for a NR PDCP, configuring the suspended radio bearer withthe configuration information; and resuming the suspended radio bearer.2. The method of claim 1, wherein the established RRC connectionincludes a NR PDCP bearer.
 3. The method of claim 1, wherein theestablished RRC connection includes a long term evolution (LTE) PDCPbearer.
 4. The method of claim 1, wherein the connection resume messageis received from a second network node that is different than the firstnetwork node.
 5. The method of claim 1, wherein configuring thesuspended radio bearer comprises using the configuration information inthe connection resume message and the stored configuration information.6. The method of claim 5, wherein the configuration information in theconnection resume message takes precedence over the stored configurationinformation.
 7. The method of claim 1, wherein the configurationinformation in the connection resume message includes securityinformation different from the security information used prior tosuspension of the radio bearer.
 8. The method of claim 7, wherein thesecurity information comprises security key information or securityalgorithm information.
 9. The method of claim 1, further comprising:upon determining the connection resume message does not includeconfiguration information for NR PDCP for the suspended radio bearer,resuming the suspended radio bearer as a long term evolution (LTE) PDCPbearer.
 10. The method of claim 1, further comprising: establishingsignaling radio bearer 1 (SRB1) NR PDCP connection with the firstnetwork node; upon receiving the connection suspend message, convertingthe SRB1 connection to a long term evolution (LTE) PDCP connection; andwherein the connection resume message is received over the SRB1connection.
 11. A user equipment (UE) capable of resuming a radio bearerin a wireless communication network, the UE comprising processingcircuitry operable to: establish a radio resource control (RRC)connection with a first network node; receive a connection suspendmessage from the first network node; store a configuration of a radiobearer associated with the RRC connection; suspend the radio bearerassociated with the RRC connection; receive a connection resume message;determine whether the connection resume message includes configurationinformation for NR packet data convergence protocol (PDCP) for thesuspended radio bearer; upon determining the connection resume messageincludes configuration information for a NR PDCP, configure thesuspended radio bearer with the configuration information; and resumethe suspended radio bearer.
 12. The user equipment of claim 11, whereinthe established RRC connection includes a NR PDCP bearer.
 13. The userequipment of claim 11, wherein the established RRC connection includes along term evolution (LTE) PDCP bearer.
 14. The user equipment of claim11, wherein the connection resume message is received from a secondnetwork node that is different than the first network node.
 15. The userequipment of claim 11, wherein the processing circuitry is operableconfigure the suspended radio bearer by using the configurationinformation in the connection resume message and the storedconfiguration information.
 16. The user equipment of claim 15, whereinthe configuration information in the connection resume message takesprecedence over the stored configuration information.
 17. The userequipment of claim 11, wherein the configuration information in theconnection resume message includes security information different fromthe security information used prior to suspension of the radio bearer.18. The user equipment of claim 17, wherein the security informationincludes security key information or security algorithm information. 19.The user equipment of claim 11, the processing circuitry furtheroperable to, upon determining the connection resume message does notinclude configuration information for a NR PDCP for the suspended radiobearer, resume the suspended radio bearer as a long term evolution (LTE)PDCP bearer.
 20. The user equipment of claim 11, the processingcircuitry further operable to: establish a signaling radio bearer 1(SRB1) NR PDCP connection with the first network node; upon receivingthe connection suspend message, convert the SRB1 connection to a longterm evolution (LTE) PDCP connection; and wherein the processingcircuitry is operable to receive the connection resume message over theSRB1 connection. 21.-32. (canceled)